<!DOCTYPE html>
<html lang="zh-cn">
    <head>
        <meta charset="UTF-8"/>
        <meta name="viewport" content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0" />
        <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1" />
        <title>两列等高</title>
        <style>
            .wraper{width:980px; border:1px #000 solid; overflow:hidden; margin:0 auto;}
            .col-sub{width:200px; background:#000;color:#fff; margin-bottom:-3000px; padding-bottom:3000px;float:left}
            .col-main{width:780px; margin-bottom:-3000px; padding-bottom:3000px;float:right}
            .col-main p{padding:20px}
        </style>
    </head>
    <body>
        <div class="wraper">
        <div class="col-sub"> <h3>这是左侧功能区块</h3></div>
        <div class="col-main"> <h3>右侧主体内容区块</h3></div>
        </div>
        <!-- <div class="wraper">
        <div class="col-main"> <h3>右侧主体内容区块</h3></div>
        <div class="col-sub"> <h3>这是左侧功能区块</h3></div>
        </div> -->
    </body>
</html>